The present invention relates to a polyaniline/carbon black composite material and a preparation method thereof, especially to an epoxy composite material containing polyaniline/carbon black and a preparation method thereof that are applied to various fields such as conductive coating or microwave absorbing material.
The research and development of conductive coatings have been over a half-century. Working as conductive layer, electromagnetic wave shielding layer and antistatic coating, the conductive coatings have broad perspective and increasing market demands. The membrane surface of the conductive coating has higher resistance, charge generated thereon is not dissipated effectively so that static charges tend to accumulate thereon. This leads to certain limitations on applications of some respects such as dust proofing and bacteria resistance in medicine, protection from electric shock in medical operations, static protection for preventing static ignition and explosion in mine environment and petrochemistry, dust-proofing for protection of integrated circuit, and fiber accumulation in spinning industry. The conductive coating is special coating or meeting various requirements. The conductive coating is coating with conductor and semiconductor properties and the conductivity is above 10−10 S/cm, being applied to various fields such as electronic and electric appliance industry, printed circuit board, switches, marine antifouling coatings, electrothermal material, and electromagnetic wave shielding, and surface protection.
While using carbon series as filler in preparation of conductive coating, carbon black (mainly high conductive furnace carbon black and acetylene carbon black), graphite and carbon fiber are mixed together. In literatures, graphite as conductive filler is added with epoxy resin and it is found that the conductivity is dramatically improved when amount of the graphite is over 50 wt. %. However, addition of graphite results in poor physical and mechanical properties and poor processability. This leads to limits on usefulness of the conductive coating.
The conductive and microwave absorbing polyaniline has features of light weight, good plasticity, easy raw materials acquisition, easy synthesis and high stability. Thus an epoxy composite material containing conductive and microwave absorbing polyaniline, and high conductive and microwave absorbing nanoscale carbon black is produced so as to overcome defects of poor physical property, poor mechanical property and poor processability caused by large amount of graphite being added. Moreover, the present invention has features of high conductivity and high microwave absorption without adding large amount of carbon black. Thus weight of carbon black added in conductive coating or microwave absorbing material is dramatically reduced so as to facilitate the applications of material in conductive elements or microwave absorbing elements.